Suitable for Caesar, from SD war 4

These are the two main lines in the rumor.

Other examples mentioned are:

O has always been a passer-by, but this time the crane has become the last BOSS.

Casting, from "Mechanical Warfare" α2

Wolves, from the machine war MX, can be understood as the prequel of MX.

ART- 1 This black historical creature should have appeared in the cyber war α3.

Valsion CF, OG series original

There are few stories about OG. It's basically the world of Shura and Caesar.